Omar rowed his boat for $4$ kilometers on each of the past $5$ days. How many kilometers did Omar row his boat altogether?
Explanation: The total number of kilometers rowed is the product of the number of kilometers rowed each day and the number of days that Omar went rowing. The product is $4\text{ kilometers per day} \times 5\text{ days}$ $4\text{ kilometers per day} \times 5\text{ days}= 20\text{ kilometers}$ Omar rowed a total of $20$ kilometers.